Regarding the commercial importance and industrial application of white products, investigation into the performance of whiteness indices and their conformity to the visual assessments is essential. In this paper, the performance of Uchida whiteness index for the evaluation of fluorescent whitening agents (FWAs) treated white specimens is investigated based on the modified CIE tinting formula. In this way, the percentage of whiteness acceptance of the fluorescent white samples with different whiteness and tinting attributes, are achieved based on the observers visual assessments. Besides, the correlations between CIE and Uchida whiteness indices as well as with the results of visual assessments are calculated. The results show that while the performance of Uchida whiteness index has been improved by modifying CIE tinting formula, the CIE whiteness index access white specimens, better. It means that, in the modified tinting region the results of visual assessments conform to CIE whiteness index better than Uchida formula. Moreover, it seems that the results of the Uchida whiteness formula closes to those achieved from CIE whiteness index in the modified tinting region.